Emission factors and species profile of vehicular ...
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2015.04.16 Emission factors and species profile of vehicular evaporative loss: China vs. US School of Environment Tsinghua University, China Hanyang MAN Dr. Huan LIU
Transcript of Emission factors and species profile of vehicular ...
2015.04.16
Emission factors and species profile of vehicular evaporative loss: China vs. US
School of EnvironmentTsinghua University, China
Hanyang MANDr. Huan LIU
Overview
Introduction
Research framework
Experiment data and analysis
Conclusion
Sever PM2.5 and O3 pollution in China
Global satellite-derived PM2.5averaged over 2001-2006
(Donkelaar et al., EHP, 2010)
Predicted Ozone level in the surface of the earth
（IPCC SRES-A2）Vehicle related source
SOA Oxidation Reactions
O3
NOx
PM2.5
NOx, O3, OH
MIR of speciesNucleation
and growth
China has been controlling exhaust VOCs to reduce PM2.5
Annual concentration of PM2.5 in China
Jingjinji
PRDYRD
Tailpipe and evaporative emission standards in China
Control strategies of vehicular evaporative emissions worldwide
EPA Tier2 0.65g(0.5) g/day for 48(72)-hour test,
0.05g/L for refueling test
EPA Tier0 2g/test for 2-hour test
EURO V/ⅤI
2g/test, 24-hour test
EURO Ⅳ(China Ⅳ)
EURO II JLEV 2g/test for 24-hour test
KLEV2 1.2g/test for 48-hour test
We need to know：
What are evaporative emission characteristics and factors in China？
How much do emissions vary between US and EURO regulations？
What is the difference of species among different type emissions？
More research is necessary to understand evaporative emission
Research Framework
Two Tier2 vehicles
China Type IV test
US 48-hour test+ 24-hour permeation
Three China IV vehicles
US 72-hour diurnal test
US Refueling Test
Sample gas in the SHED and analysis using GC-MS/FID method
Species analysisRVP of test fuelPurge rate during driving cyclesWeight of canistersEmission factors
SHED tests
Characteristic, emission process, species profile……
Emission factors, control efficiency and the ratio between China Ⅳ and Tier2 vehicles
Purge properties of canisters
Tier2 vehiclesChina Ⅳ vehiclesNote:Define purge rate larger than 3L/min as efficient
Purge volume and purge rate during preconditioning driving cycles
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The relationship between purge volume and the weight change of the canister
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The relationship between vapor emission, vapor generation and canister capacity
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VOCs profiles of China Ⅳ vehicular evaporative emissions
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VOCs profiles of Tier2 vehicular evaporative emissions
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Comparison of OFP between evaporative emissions and tailpipe emissions
(Wang, J., et al. Science of Science of the Total Environment, 2013)
An interesting results in ORVR tests
Comparison of vapor generation for two type vehicles during ORVR tests
Relationship between emissions measured by GC-MS and FID
( Test1-3 is China IV vehicles Test4-5 is Tier2 vehicles )
Take home message
The emission factors of China IV vehicles are 2-70 times higher than those of Tier2 vehicles for reasons of little capacity of canister and bad purge performance.
The Euro standards could only force vehicles purge under high speed (above 60 km/hour) and high VSP，which cannot meet the needs of urban driving conditions, while US standard is beneficial for vehicles to purge under almost all conditions.
Although the amount of emission evaporations was comparable to that of tailpipe emissions for China and US vehicles under Chinese fuel condition, vehicles evaporative emissions control is essential because of its higher OFP.
